Without limiting the scope of the invention, its background is described in connection with marine seismic exploration of the earth's strata located below a body of water, usually a sea but could be inland lake or rivers as an example.
In the field of marine seismic exploration, seismic prospecting has been used in the industry to obtain the survey data necessary for directing offshore or inland lakes and rivers drilling operations. Seismic prospecting of hydrocarbons and other natural resources found in relatively deep formations of the earth's crust has required the use of offshore survey data. Such data can be collected by using mobile survey vessels equipped with seismic exploration devices of type described in U.S. Pat. Nos. 4,956,822 (the '822 patent) and 5,469,404 (the '404 patent) to Barber, et al.
The seismic exploration devices described in the '822 and '404 patents are multiple air gun systems. The devices are designed to maximize the efficiency of the air guns by positioning the air guns in a particular geometry with a particular spacing. Changes in the specific arrangement of the air guns can result in the devices providing inaccurate, or less reliable, data. Since the majority of seismic exploration occurs in the open waters of seas and oceans, reliable transportation, deployment, and retrieval of seismic exploration devices is needed to prevent damage to the seismic exploration device and misalignment of the air guns. In addition, the equipment must provide stability to the seismic exploration device during their operation. Since the seismic exploration devices are towed behind a vessel, it is necessary to provide a safe, sturdy, reliable manner by which to launch recover and maintain a connection between the vessel and the deployed seismic exploration device, especially while surveying in rough seas while not effecting its operation. In addition, a reliable storage apparatus is required for containing the seismic exploration device while in transit to and from the survey area.
Few, if any, handling devices have been developed which provide the safety and stability in transportation, deployment and retrieval of seismic exploration devices. A need has therefore arisen for such a handling device so that the data obtained from seismic exploration devices remains accurate and dependable.